With the development of communications technologies, innovation of the network field steps far behind that of the server end, and a user requires that the network be configured more rapidly and conveniently; therefore, people starts to focus on a programmable network, and a software defined network (SDN) emerges.
The SDN refers to an open environment derived from a conventional closed network, in which programming can be implemented just like a computer; an easily managed network virtualization layer is created, network control is decoupled from physical infrastructure, and a third party develops a network application program to control running of the network. The OpenFlow technology is one manner of implementing the SDN, and can enable users themselves to define traffic and decide a transmission path of the traffic in the network.
An OpenFlow network formed based on the OpenFlow technology includes an OpenFlow controller and an OpenFlow switch. The OpenFlow switch is a core component, and includes three parts, namely, the OpenFlow protocol, a secure channel, and a flow table.
According to the OpenFlow protocol, when establishing a connection to the controller, the OpenFlow switch needs to report a capability of the switch to the controller, where the capability includes the number of flow table levels currently supported by the switch, the number of entries in each level of flow table, and a flow table match field type in each level of flow table. The controller formulates a flow rule of the switch according to the capability report of the switch, and delivers the flow rule to the flow table of the switch. However, if an application scenario of the switch changes, and consequently a type of a service needing to be forwarded by the switch device changes and therefore a flow table match field supported by the switch cannot satisfy the changed service type, the controller cannot generate a corresponding flow rule, and further cannot implement a corresponding forwarding service. When the application scenario of the switch changes, the OpenFlow switch is disconnected from the network, and software and even hardware of the switch are re-configured; then, the switch re-accesses the switch network, and re-establishes a connection to the controller; and finally, the controller generates a corresponding flow rule to implement a corresponding forwarding service.
With this method, although normal service forwarding can be finally implemented when an application scenario of a switch changes, the OpenFlow switch must be disconnected from the network to implement the service forwarding; therefore, a service switchover adaptation capability of the entire network system is poor, affecting the working efficiency.